Induction of TNF-α, ICAM-1, IL-17, and IFN-γ expression during elicitation of CHS. Groups of 4 C57BL/6 mice were sensitized with 0.25% DNFB on days 0 and +1. On day +5, the sensitized and groups of control naïve mice were challenged with 0.2% DNFB. Challenged skin was excised at 1, 2, 3, and 4 hrs. post-challenge and snap-frozen. Skin from naïve/non-challenged (NNC) mice was excised as a control. Whole cell RNA was prepared and was used to assess mRNA expression of TNF-α, ICAM-1, IL-17, and IFN-γ in the skin samples by quantitative RT/PCR. The mean expression level for each of 4 samples per group ± SEM is shown. All results are representative of two individual experiments. *p ≤ 0.05.